This invention relates generally to devices used to implant catheters in a recipient, and more particularly to the implanting of relatively long catheters. The invention also relates to units adapted to store catheters for use in venipuncture, and after venipuncture to advance a long catheter into the patient while maintaining the aseptic condition of the catheter.
Generally, catheters now in use for intravenous applications may be classified as "needle-inside" or "needle-outside". These classifications result from the provision of a needle concentrically arranged with respect to a catheter to be placed in the vein of a patient. This concentric arrangement has been found to be relatively satisfactory, but does result in certain problems. For example, ordinarily it is necessary to provide access to the body through an incising element, then to provide a conduit for fluid passage using a hollow tube or catheter. Using a single element as the incising element and conduit is not recommended due to the danger of internal damage when the needle or incising element is left in place. Accordingly, the concentric arrangement of incising element and conduit is utilized. However, a long catheter arranged outside the needle is likely to be contaminated and is difficult to advance into the vein.
A particular problem has been found in devices of this kind in effectively removing the needle both from the venipuncture device and from the site following venipuncture. While the needle remains in the patient, there is a possibility of injury to the vein of the patient. Similarly, once the catheter has been inserted and the needle slidably removed from the patient, there remains the danger of the needle puncturing the catheter. Likewise, during insertion, when the catheter hits a restriction, many times the catheter is pulled back, increasing the risk of being cut by the needle heel.
A number of catherter insertion devices now available provide for the storage of long, flexible catheters within a drum-like receptacle. When the receptacle is rotated relative to its base, the catheter is advanced through the external needle. This method is used after venipuncture to advance the catheter into the patient. A problem remains, however, in removing the needle and catheter insertion device after venipuncture. In one present device, disclosed in U.S. Pat. No. 3,561,445, the needle is slid rearwardly on the catheter to the area proximate the catheter hub. The needle cannot be entirely removed, however. In another device, disclosed in U.S. Pat. No. 3,995,628, a slit needle is used and the catheter withdrawn from the needle. However, in both cases there is a danger of cutting or perforating the catheter, and the removal process is difficult and messy.
Accordingly, it is an advantage of the present invention to provide an improved needle-inside catheter insertion device in which the needle may be removed from the patient immediately following venipuncture, while retaining access to the vein of the patient for insertion of a long catheter.
It is an additional advantage of the present invention to provide such a device in which the catheter may be readily and easily advanced into the patient without manually engaging the catheter.
Still another advantage is to provide a catheter dispenser which may be discarded after the catheter is implanted, in order to facilitate the connection of extrinsic equipment and to ensure the patency of the catheter.
These and other advantages of the invention will become apparent from a consideration of the specification and claims.